Dynamic service binding providing transparent switching of information services having defined coverage regions

ABSTRACT

It is determined whether a location of a mobile device is within a coverage region of a first information service. Communications for the first information service are redirected to a second information service when the location of the mobile device is not within a coverage region of the first information service. The second information service generally has a coverage region encompassing the location of the mobile device. Communications between a mobile device and a first information service are redirected to another information service when properties of the new information service are determined to meet predetermined criteria set by a user of the mobile device, by an application, or both. In yet another aspect of the invention, Replacement of information services can be “aggressive” or “non-aggressive.” Communications between a mobile device and an original information service are redirected to another information service when the original information service fails.

FIELD OF THE INVENTION

The present invention relates to communication systems and, moreparticularly, relates to communication systems where devices travelbetween areas, such as cellular phone systems.

BACKGROUND OF THE INVENTION

The mobility of devices has become highly desirable. Moreover, manydevices now interact with wireless systems and, consequently, manydevices are blurring the line between wireless networks and traditionalcomputer systems. For instance, some personal digital assistants canconnect to wireless networks, such as a cellular phone network, whilemany cellular telephones now connect to the Internet through wirelessnetworks.

A benefit of mobile devices is that the devices can be used to connectto local information services, such as information services providinglocal traffic, weather, or telephone numbers, when traveling. It ispossible for a person using a cellular phone to determine the phonenumber of a local pizza parlor, for instance, or learn what the trafficis like on a major thoroughfare.

While the mobility of devices is desirable, it can also create problems.For instance, information services that provide traffic reports are onlyvalid for particular areas. Therefore, a person whose cellular phone isset to connect to a local Internet site providing local trafficinformation will not be of use when the person is at a remote location.Similarly, information services that provide directory services such astelephone numbers and addresses usually have only a certain geographicalarea for which the provided information is relevant. Outside thisgeographical area, the information is generally irrelevant.

Thus, what is needed are techniques for allowing mobile devices toaccess services when the mobile devices travel between areas.

SUMMARY OF THE INVENTION

The present invention provides methods and apparatus for dynamic servicebinding, providing transparent switching of information services. Ingeneral, the information services have defined coverage regions, suchthat a mobile device will interact with one information service in afirst location but the mobile device may interact with anotherinformation service when the mobile device is in another location.

In one aspect of the invention, it is determined whether a location of amobile device is within a coverage region of a first informationservice. One or more communications for the first information serviceare redirected to a second information service when the location of themobile device is not within a coverage region of the first informationservice. In an exemplary embodiment, the second information service hasa coverage region encompassing the new location of the mobile device.

In another aspect of the invention, communications between a mobiledevice and a first information service are redirected to anotherinformation service when one or more properties of the new informationservice are determined to meet predetermined criteria. In oneillustrative embodiment, the predetermined criteria may be set by a userof the mobile device, by an application, or both.

In yet another aspect of the invention, replacement of informationservices can be “aggressive” or “non-aggressive.” For instance, a newinformation service may become available to a user, and the newinformation service, if adjudged to more adequately meet preferences ofthe user, will replace an original information service being used by theuser, even if the original information service is still valid. This iscalled aggressive replacement of information services herein. In anon-aggressive replacement, the original information service, if stillvalid based on a location of the user, will not be replaced and willremain in use.

In yet another aspect of the invention, communications between a mobiledevice and an original information service are redirected to anotherinformation service when the original information service fails.

A more complete understanding of the present invention, as well asfurther features and advantages of the present invention, will beobtained by reference to the following detailed description anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary application server interactingwith a wireless device through a wireless network, with carrier locationtechnology, with information services through the Internet, and withmedia in accordance with one embodiment of the present invention;

FIG. 2 is a block diagram of an exemplary dynamic service binding systeminteracting with a mobile device through an application, with wirelessnetwork, and with the Internet, in accordance with one embodiment of thepresent invention;

FIG. 3 is an exemplary table representing service properties, inaccordance with one embodiment of the present invention;

FIG. 4 is an example of a capability requirement, in accordance with oneembodiment of the present invention;

FIGS. 5 through 7 are exemplary methods for dynamically bindinginformation services, in accordance with embodiments of the presentinvention; and

FIG. 8 is an exemplary table representing a portion of a serviceproperties database including user preferences, in accordance with oneembodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

There are applications in which the location of a person or an object isused to shape or focus the service. The integration of technologies thataccurately determine location, such as global positioning system (GPS)information, into many devices makes these types of applications moreconvenient by sparing users the need to self-describe their locations.These technologies also enable new applications, such as a drivingassistant that proactively alerts a driver to traffic congestion aheadand suggests an alternate route. These sorts of applications areexpected to be especially valuable to mobile users.

But just as mobility is a core driver of these types applications, italso presents certain challenges. In particular, mobility creates thepossibility that a change in location may result in the loss of aparticular information service in communication with an application. Bynature, many information services are associated with a certaingeographical area, called a “coverage region” herein. Atraffic-congestion reporting information service, for example, may offerinformation for only certain metropolitan areas. Therefore, aninformation service that is valid for one location may not be valid foranother. As a user of an information service moves, that informationservice may eventually become invalid. It should be noted herein thatthe term “user” includes a mobile device whose location can bedetermined.

It is also true that, as one information service becomes invalid due toa change in location, another information service of the same kind maybecome valid. As a particular example, suppose a user subscribes to thedriving-assistance application mentioned above, which offersnotification of traffic congestion. As the user travels from New York toPhiladelphia, there may be different traffic congestion reportinginformation services available—one for New York City, one for the NewJersey Turnpike, and another for the Philadelphia area. It would bedesirable for the driving assistance application to switch from areporting information service that is no longer valid for the currentlocation to another that does offer service for the current location,and to do so in a manner that is transparent to the user and to theapplication being used by the user. This is referred to as “dynamicservice binding” herein, as an information service is “bound” to aparticular application through certain techniques.

Consider what might be beneficially used to implement dynamic servicebinding in the specific case of the driving assistant example, forinstance. First, a dynamic service binding system should keep track ofvarious reporting information services and their respective coverageregions. Second, the dynamic service binding system should periodicallyobtain the location of a user (e.g., a location of a mobile device usedby the user) to determine whether the current reporting service is stillvalid for the current location. If not, the dynamic service bindingsystem should select an appropriate information service valid for thenew location and switch to the valid information service.

Note that, since it is assumed that the various traffic reportinginformation services used will be from independent providers, it is alsoassumed that the various information services may have differentprogramming interfaces, including different invocation mechanisms, andthat the information services will use different authentication andauthorization mechanisms. Thus, it is beneficial for dynamic servicebinding to also manage these issues.

It may be possible for individual applications to perform dynamicservice binding. Given the level of support required, however, and thefact that dynamic service binding is useful across a wide range ofapplications for mobile users, it is desirable to factor this supportout of applications, and offer it in the form of a dynamic servicebinding system that acts as an intermediary between applications andlower-level services. FIG. 1 shows an exemplary location for a dynamicservice binding system within a larger application architecture.

Referring now to FIG. 1, a block diagram is shown of an exemplaryapplication server 100 interacting with a wireless device 110 through awireless network 120 and a wireless gateway 125, with carrier locationtechnology 140, and with information services 160-1 through 160-N(collectively information services 160) through, for instance, theInternet 150. Application server 100 comprises a memory 130, a processor180, and a media interface 175. Application server 100 interacts withmedia 170 through media interface 175. Memory 185 comprises anapplication 130 and a dynamic service binding system 135.

Application server 100 generally resides on the Internet, such asInternet 150. As another example, in an intranet, the application server100 could be a server on the intranet and connected to an access pointor several access points.

Generally, wireless device 110 accesses application 130 through wirelessnetwork 120 and wireless gateway 125. The application 130 accesses oneor more of the information services 160. For instance, the wirelessdevice could be executing an Internet browser (not shown) that isaccessing an application 130 that is a JAVA applet in order to determinea telephone number for a local restaurant.

Because quite a few different applications can benefit from changinginformation services 160 as the location of wireless device 110 changes,the dynamic service binding system 135 provides an interface to theapplication 130 and provides transparent binding of one or moreinformation services 160 to the application 130.

Usually, the dynamic service binding system 135 determines the locationof the wireless device 110 via carrier location technology 140, which isgenerally implemented by wireless network 120. For instance, somecellular technology now uses a GPS receiver built into a wireless device110, and the wireless network would contain carrier location technology140 in order to determine the location of a wireless device 110. Carrierlocation technology 140 is intended to encompass any technique fordetermining a location of a mobile device. Regardless of the techniquebeing used, the dynamic service binding system 135 uses the location ofwireless device 110 in order to select an information service 160 tobind to the application 130. Thus, location is a criterion used to“validate” an information service. When the location passes outside of acoverage region of an information service 160, the information service160 is assumed to be invalid. Other criteria used to validate aninformation service 160 are described in more detail below.

Illustratively, the dynamic service binding system 135 usually providesan interface to the application 130 suitable for interacting with theapplication 130. For instance, if the application 130 expects aninformation service 160 to be a mapping information service, the dynamicservice binding system 135 provides a mapping information serviceinterface. This is described in more detail below.

In one embodiment, a dynamic service binding system 135, as described inadditional detail below, changes a binding between an application 130and an information service 160 by changing a reference to theinformation service 160. However, any technique that is used to director redirect communications between the application 130 and aninformation service 160 may be used to bind application 130 andinformation service 160.

As explained in more detail below, application 130 generally requests acertain information service 160 meeting particular criteria, generallyexpressed in the form of capability requirements. In general, aninformation service 160 will have a programmatic interface (not shown),i.e., which is accessed by application 130 and not by users of awireless device 110. The dynamic service binding system 135 determineslocation of the wireless device 110 and initializes connections to anappropriate information service 160, if an appropriate informationservice 160 is found. The information service 160 is bound to theapplication 130, preferably through a reference as described below. Asthe wireless device 110 travels, it may leave the coverage region of theinformation service 160. Alternatively, the wireless device 110 mayenter a coverage region of a “better” information service 160. The“better” information service 160 is determined via certain criteria.Moreover, the original information service 160 may fail. As anotherexample, a new information service 160 may become available, even if themobile device does not change location. The new information service maybe better than the current information service 160, as determinedthrough certain criteria provided by the user or the operator of theapplication server 100. These conditions could cause the originalinformation service 160 to become invalid and the dynamic servicebinding system 135 will determine the invalidity of the informationservice 160 and will bind the application 130 to a new informationservice 160. Communications for the original information service 160will be redirected to the new information service 160. This redirectionshould be totally transparent to the application 130.

It should be noted that the application 130 may also be part of wirelessdevice 110.

Although wireless networks and wireless devices are used as examplesthroughout the present disclosure, the present invention is not limitedto wireless networks and wireless devices. For instance, a person with alaptop computer connected to telephone lines might desire to connect toa directory information service when the person is in a location farfrom a normally used directory information service. An application 130may be able to determine the location of the laptop through, forinstance, dialing properties. The dynamic service binding system 135 canthen use the dialing properties to properly select a directoryinformation service for the wireless device 110.

The following are examples of what functions a dynamic service bindingsystem 135 might provide.

For any information service 160 in use by an application 130, dynamicservice binding system 135 should be able to monitor the validity of theinformation service 160 (e.g., whether the location of the mobile deviceremains within the coverage region for the information service 160) andlook for another information service 160 when the current informationservice 160 becomes invalid. If an information service 160 is found thathas the capabilities the application 130 requires, the dynamic servicebinding system 135 should be able to change bindings dynamically so thatthe change in providers is transparent to the application 130. Thisincludes performing whatever initial steps are necessary before theinformation service 160 is used (e.g., authentication).

A dynamic service binding system 135 should also be able to changebindings when an information service 160 that meets preferences of theuser becomes available for a new location. In this example, the newinformation service 160 exceeds the original information service 160 viapredetermine criteria such as user preferences.

Dynamic service binding should also be provided in case of informationservice failure. This is called “failover” herein. In case ofinformation service failure, the dynamic service binding system 135should select another information service 160 with a compatibleinformation service 160, assuming a compatible information service 160exists, and bind the application 130 to the compatible informationservice 160.

Dynamic binding should also accommodate wholesale changes in the serviceenvironment, as when there is a transition from a general, outdoorservice environment to a specialized, perhaps indoor environment. Inthis case, the dynamic service binding system 135 may need to switchinformation services 160 for several location services, and may need toswitch carrier location technology 140 (or an interface thereto, asdescribed in reference to FIG. 2).

As is known in the art, the methods and apparatus discussed herein maybe distributed as an article of manufacture that itself comprises amachine readable medium, such as one of a number of media 170,containing one or more programs which when executed implementembodiments of the present invention. For instance, the machine readablemedium may contain a program configured to dynamically bind application130 to one or more information services 160. The machine readable mediummay be a recordable medium (e.g., a hard drive or an optical disk) ormay be a transmission medium (e.g., a network comprising fiber-optics,the Internet 150, a wireless network 120 using time-division multipleaccess, code-division multiple access, or other radio-frequency channel,such as that used on wireless network 120). Any medium known ordeveloped that can store information suitable for use with a computersystem may be used.

Processor 180 can be configured to implement the methods, steps, andfunctions disclosed herein. The memory 185 could be distributed or localand the processor 180 could be distributed or singular. The memory 185could be implemented as an electrical, magnetic or optical memory, orany combination of these or other types of storage devices. Moreover,the term “memory” should be construed broadly enough to encompass anyinformation able to be read from or written to an address in theaddressable space accessed by processor 180. With this definition,information on a network is still within memory 185 because theprocessor 180 can retrieve the information from the network. It shouldbe noted that each distributed processor that makes up processor 180generally contains its own addressable memory space. It should also benoted that some or all of dynamic service binding system 135 can beincorporated into an application-specific or general-use integratedcircuit.

Referring now to FIG. 2, a block diagram shows an exemplary dynamicservice binding system 135 in more detail. Exemplary dynamic servicebinding system 135 interacts with the mobile device 290 throughapplication 130, a wireless network 250, and an information service160-1 through the Internet 150. Only one information service 160 isshown for simplicity.

Dynamic service binding system 135 comprises, in this example, a serviceproxy 210, a service adapter 220, a network interface 221, a carrierlocation adapter 225, a context provider 245, a location service factory230, and a service properties database 240. Service proxy 210 comprisesa reference 215. Location service factory 230 comprises a contextinterface 235 and context 237. Context 237 comprises a position 238 of amobile device.

Application 130, as described above, is an application that makes use ofan information service. A typical example is a personal navigationapplication that allows users to request maps of particular locations,driving instructions from one place to another, and the locations ofstores and other points of interest.

Service proxy 210 is a module with a reference 215 to a service adapter220, and preferably having the same interface as the service adapter220. The value of the reference 215 can be modified in order to refer toa different service adapter 220, in case, for example, the originalservice adapter 220 fails or a mobile device changes locations. Theservice adapter 220 is a local proxy for the Internet-hosted informationservice 160-1. The service adapter 220 manages the low-level protocol ofthe Internet-hosted information service 160-1 and managesinitialization-time functions such as authentication. The serviceadapter 220 is linked to one information service 160, such asinformation service 160-1. Thus, once reference 215 is set for aparticular service adapter 220, the application 130 is bound to aspecific information service 160, such as information service 160-1. Itmay be possible for one service adapter 220 to link to more than oneinformation service 160. In this situation, the service adapter 220would be adapted to have its own reference (not shown) as to whichinformation service 160 the service adapter 220 is to reference.

It should be noted that a single application 130 could access multipleservice adapters 220 in order to access multiple information services160. For instance, an application provider may contract with oneinformation service provider for maps and another for directoryinformation. Or, the application provider may allow the user to choosehis or her information service providers. In these instances, thereference 215 may have multiple references, each reference binding theapplication to a specific service adapter 220. Alternatively, asdescribed above, a service adapter 220 may be made to access multipleinformation services 160.

An information service 160, such as information service 160-1, is aservice provided via the network interface 221 over the Internet,typically using the HTTP protocol. Examples of services are directoryservices providing telephone numbers and locations of residences andbusiness and mapping services providing maps of interstate roads,intrastate roads, and perhaps points of interest. An information service160 does not have to be an Internet-based service, although thattypically will be the case. For example, the information service 160-1could reside on an asynchronous transfer mode network, an intranet, a“plain old telephone system” (POTS) network, or a cellular phone networkoffering, for instance, text information via an information service. Aninformation service 160 can be any service for which a user can withdrawinformation requested by the user through an application.

The carrier location adapter 225 is an adapter for the particularcarrier location technology 140 that determines the location of themobile device 290. The carrier location adapter 225 will typically use alocation-determining service provided by the wireless carrier, such as awireless carrier controlling wireless network 250. The carrier locationadapter 225 may have a timing function, so that the carrier locationadapter 225 will periodically ascertain the location of a mobile device290 via the carrier location technology 140. Alternatively, the locationservice factory 230 can periodically query the carrier location adapter225 in order to determine the location of the mobile device 290.Furthermore, some cellular systems will “hand off” cellular phone userswhen the users move from cell to cell. This handing off process couldtrigger a message to or through the carrier location adapter 225informing the location service factory 230 of the updated location of acellular phone user.

The location service factory 230 is a module that performs, among otherthings, the functions of service adapter 220 creation and rebinding.This is described in more detail below.

The service properties database 240 is a database containing serviceproperties, examples of which include a coverage region for aninformation service 160 and, in the case of a service that returns maps,the image formats the service is capable of providing. The serviceproperties database 240 is described in additional detail in referenceto FIG. 3.

The context provider 245 is a module delivering user contextinformation, denoted as context 237. Context 237 is converted to a userposition 238 by the location service factory 230. The context 237 can bein GPS coordinates, for instance, and the user position could bemaintained in the GPS coordinates or converted to a simpler location,such as “Connecticut.” The context provider 245 could be a modulecontaining a location for a user that the user has entered, forinstance. For cellular phone systems, the user may only be able to belocated via knowing in which cell the mobile phone used by the user is.The context provider 245 can then inform the context interface 235 of atleast where the cell is or an area encompassed by the cell.Additionally, the context provider 245 may also determine when anotherinformation service is registered in the service properties database240, as registration of another device can be a criterion used todetermine validity of an information service.

The context interface 235 is an interface through which contextinformation is delivered. The context interface 235 is adapted to readcontext information and, when required, convert the context informationto a position of a mobile device. Context information generallycomprises position information about a mobile device. However, contextinformation may also comprise messages about the status of theinformation service. For instance, as described in more detail below,the context information can be a message indicating failure of theinformation service.

It should be noted that there could be multiple carrier locationadapters 225 corresponding to various mobile devices 290. For instance,a mobile device 290 might use cellular service having GPS locationservices, while another mobile device 290 might not have GPS locationservices. These two mobile devices would then have two different carrierlocation adapters 225.

It should be noted that the different entities making up dynamic servicebinding system 135 are merely exemplary. The entities could be combined,further subdivided, or deleted. For instance, the location servicefactory 230 and the service proxy 210 could be combined. As anotherexample, the location service factory 230 could be divided into aportion handling context and a portion that changes reference 215,instantiates service adapter 220, and determines when to redirectcommunications between an application 130 and an information service 160based on validity of the information service 160. Additionally, thedynamic service binding system 135 may not contain the network interface221, which can be separate. The carrier location adapter 225 and thecontext provider 245 can also be separate from the dynamic servicebinding system 135. In the examples given herein, many of entities canbe implemented through software modules. However, portions of one ormore entities can also be implemented in hardware, such as through anintegrated circuit.

Turning now to FIG. 3, an example of the service properties database 240is shown. In this example, the service properties database 240 isimplemented as a table, which has a number of service properties. Thereare two mapping services and two directory services, each of which has adefined coverage region. The simple terms of “Northeastern U.S.,” “NewYork,” and “Westchester County, N.Y.” can be converted, if desired, to anumber of coordinates demarcating the coverage region. It should benoted that these coverage regions can be completely arbitrary. Inparticular, coverage regions do not necessarily correspond to the cellsof wireless communications services. The “capability names” arecapabilities provided by the service, and the “formats” are thosesupported by the service. The “cost” is an example of how much eachservice costs for access to the information the service provides. The“specialty” gives additional text about the information provided by theservice.

Generally, the mobile service provider (e.g., cellular phone carrier)populates the service properties database 240. However, as describedbelow, user preferences may be added to the service properties database240. This may entail giving the user access to the service propertiesdatabase 240 or having the mobile service provider ask the user his orher preferences and adding the preferences for the user to serviceproperties database 240.

As described in more detail below, the cost and specialty properties(and any properties added via preferences of a user) can be used tovalidate an information service. For instance, a user could indicate apreference for only free services. Thus, if the user is in WestchesterCounty, New York, the location service factory 230 could select the freedirectory service. Alternatively, under the “aggressive” schemedescribed below, the location service factory 230 would select thedirectory service having the per access fee because this directoryservice has more information about the particular area the user is in.User preferences are more specifically described in reference to FIG. 8below.

The application 130 generally requests from the location service factory230 an information service 160 meeting certain criteria. In a request,the application 130 includes one or more “capability” sets that specifyits requirements and preferences. A capability set, as shown in FIG. 4,comprises a name and a set of values. A capability requirement is a nameand a single value. In the example of FIG. 4, there are two capabilitysets, <“image-formats”, “JPEG GIF”> and <“image-formats”, “TIF”>, butthree capability requirements, <“image-formats”, “JPEG”>,<“image-formats”, “GIF”> and <“image-formats”, “TIF”>. The registeredcapabilities, stored in service properties database 240, of aninformation service 160 “satisfy” a set of required capabilities if, foreach capability requirement, the registered capabilities for aninformation service 160 have a capability of the same name that includesthe value of the required capability. For instance, <“image-formats” ,“GIF JPEG”> satisfies <“image-formats”, “GIF”>. In the example of FIG.3, a capability requirement of <“text-formats”, “TXT”> is met by bothdirectory services but not by either mapping service. The capabilitysets of <“image-formats”, “GIF”>, <“text-formats”, “TXT”> is met only bythe directory service for Westchester County, N.Y.

Generally, when an application 130 requests an information service 160that meets capability requirements, the capability sets are assumed tobe in a preference order, with the highest capability sets listed first.For example, in FIG. 4, the capability set of <“image-formats”, “JPEGGIF”> is assumed to be preferred over the capability set of<“image-formats”, “TIF”>. This preference in capability sets may be usedto sort candidate information services 160, if desired.

Turning now to FIG. 5, an exemplary method 500 is shown for dynamicallybinding information services, in accordance with one embodiment of thepresent invention. Method 500 is performed by a dynamic service bindingsystem 135 in order to bind an information service 160 to an application130 and to rebind information services 160 when certain criteria aremet.

Method 500 begins in step 510 when an application 130 requests ainformation service 160 meeting particular criteria. As described above,the request by the application 130 includes one or more capability setsthat specify requirements and preferences of the application 130. Thefirst capability set is generally taken as the most preferred. In step515, the capability sets are compared, generally in order of preference,with capabilities for information services 160. The capabilities of theinformation services 160 are stored as properties in the serviceproperties database 240, as shown in FIG. 3. The properties stored inthe service properties database 240 contain the capabilities of allinformation services that are registered with the application server 100having the service properties database 240. If no information service160 is found (step 520=NO), then a failure is reported. This occurs instep 525. If one or more information services 160 that fulfill one ofthe capability requirements are found (step 520=NO), a service adapter220 is instantiated for the first information service in a list of foundinformation services and signaled to initialize itself (step 530). Thelist is generally a candidate list sorted via certain criteria, such aspreferences given by the application, user preferences, or both. Theservice adapter 220 may at this time, for testing the informationservice 160 or for authentication, communicate with the informationservice 160. A service proxy 210 is then instantiated for the serviceadapter 220 and a reference to the service proxy 210 is returned to theapplication 130. This also occurs in step 530.

The application 130 is bound to the information service 160 via areference placed in the service proxy 210. This occurs in step 535. Thereference in the service proxy 210 causes communications from theapplication 130 to be directed to the service adapter 220 and thereforeto a specific information service 160.

At some time, the application 130 makes a service invocation on theservice proxy 210, which passes the service invocation through to theservice adapter 220. The service adapter 220 performs its function ofadapting the invocation to the protocol used by the information service.In the case of an Internet service, this will include opening a networkconnection to the information service, serializing the objects of theinvocation argument, and writing them to the network stream. Datareturned in the stream should be deserialized into objects to bereturned to the application 130 through the service proxy 210.

Once the information service has been bound to the application 130,there is a determination of whether the information service 160 is stillvalid. This occurs in step 540. This determination is usually periodic,but need not be. For example, the determination could be driven bymessages from a cellular phone system that a mobile device has beenpassed off to another cell. These messages may occur relativelyrandomly. In the example of FIG. 5, a criterion used to determinevalidity of a service is location. When the location of the mobiledevice is determined to be outside of the coverage area for theinformation service 160 currently bound to the application 130, then themethod continues in step 515. Consequently, a new information service,if one is found (step 520), is selected, started (step 530), and boundto the application 130 (step 535). This example just described is asimple example where the location of a mobile device is determined andthe method 500 determines whether the location is within the coverageregion of the current information service.

It is also possible to have more complex procedures for determiningwhether an information service is valid. For example, a more complexmethod 600 for replacing services based on the user moving in and out ofservice coverage regions is shown in FIG. 6. Steps 510 through 535 arethe same as in method 500 of FIG. 5.

In step 605, an application 130 instructs the location service factory230 that the application 130 requires that the information service towhich the application 130 is bound to periodically have validity of theinformation service determined. The application 130 includes, in amessage for example, a reference to the carrier location adapter 225that corresponds to the mobile device using the application 130, and atime interval specifying how often to evaluate information servicereplacement. The time interval is used to determine when to perform step610. As a response to step 610, the location service factory 230 beginsa process through which the location service factory 230 will receiveperiodic notification of the position of the mobile device. This may bethrough using a periodic notification function provided by the carrierlocation technology or its carrier location adapter, or one provided bythe location service factory 230 itself. Notifications are deliveredthrough the context interface 225 of the location service factory 230.

Upon each update of the location of the mobile device (e.g., receivedthrough notification or its own periodic requests) in step 610, thelocation service factory 230 evaluates whether the current informationservice in use is still valid for the location of the mobile device, orwhether there is an information service 160 that better meets thecapability requirements requested by the application 130. Replacementmay be aggressive or non-aggressive. A list of candidate informationservices, if there are any candidates, is determined in step 620 bycomparing the capability requirements given by the application 130 withcapabilities, for the information services, stored in the serviceproperties database 240. The order in which the capability requirementsare given by the application 130 is assumed, in an embodiment, to be inorder of preference by the application 130. Additionally, userpreferences or preferences set by the application server owner may beused to set an order. For aggressive replacement, the existinginformation service 160 is replaced (step 625) if it is not the firstservice in the list. For non-aggressive replacement, the existingservice is replaced only if it is not in the list of candidates (step630). All candidate information service 160 evaluations includedetermining whether the current location for the mobile device is in thecoverage region of an information service 160.

It should be noted that the user preferences and capability requirementsare criteria that can be used to sort the candidate list. It is alsopossible to determine a value for each information service 160 in thecandidate list, according to the criteria. In the case of sorting theinformation services, the sort order, which can be given values,determines which information service 160 should be chosen. It is alsopossible for the candidate list to be not sorted and have, instead,values assigned to each information service 160 defined by the criteria.

Another criterion used to determine a validity of an information service160 is information service failure. This is shown in FIG. 7, wheremethod 700 uses information service failure to determine validity of aninformation service 160. Steps 510 through 540 are the same as in FIG.5. A service adapter 220 can determine that the information service 160to which it is associated has failed, for instance when the informationservice 160 fails to respond or is unavailable. When the informationservice 160 is determined to be invalid in step 540 (step 540=YES), theservice adapter 220 signals invalidity of the information service 160 tothe service proxy 210, for instance, by issuing a ServiceFailureexception to the service proxy 210. The current service adapter 220 andbinding are removed in step 710. The current service adapter 220 isunloaded from memory and the binding is removed by removing thereference to the service adapted from the service proxy 210.

The service proxy 210 may then initiate service replacement by, forinstance, sending a replaceService message to the location servicefactory 230 through the context interface. This would continue themethod in step 515. In step 515, the location service factory 230 firstobtains the capability requirements of the original information service160 from the service proxy 210. Using the capability requirements, asuitable replacement candidate is determined, via the same proceduredescribed above in steps 520 through 535. If a replacement candidate isfound (step 520=YES), a service adapter 220 is instantiated for theinformation service 160 and the service adapter 220 is signaled toinitialize itself, also as described above (step 530). The locationservice factory 230 then sends, for example, a setAdapter message to theservice proxy 210 containing a reference to the new service adapter 220(step 530). The reference to the service adapter 220 is placed in theservice proxy 210 in order to bind the application 130 to theinformation service 160 (step 535). The service proxy 210 will thenretry connecting to the information service 160 in order to fulfill anyoutstanding request by the application 130. If the application 130 hasregistered to be notified of a service replacement, a notificationcontaining the name of the replacement service is sent at this time.

The information service replacement may be generalized to“opportunistic” service replacement by allowing arbitrary events totrigger information service replacement evaluation. For example, theaddition of a newly available service to the service properties database240 may be such an event. As with location, in which the locationservice factory 230 indicates interest in location events by registeringwith the carrier location adapter, the location service factory 230registers interest in particular events with a context provider. Thiscontext provider delivers context events through the context interfaceof the location service factory 230.

Other events to trigger replacement evaluation could be userpreferences. If a user chooses to preferentially access free services,and a free information service becomes available as the user enters thecoverage region of the free service, the current information service inuse by the user may be replaced if the current service charges accessfees. For instance, in FIG. 8, a portion of service properties database240 is shown having user preferences and user carrier information. FromFIG. 8, it can be seen that USER A prefers free information services andthe replacement of information services should be performed in anon-aggressive manner, as described above. By contrast, USER B preferscomprehensive information services, which may or may not be free. TheUSER B also prefers that the replacement of services be handled in anaggressive manner, as described above. Additionally, the userpreferences may be used to sort a candidate list of informationservices. Thus, for USER A, a free information service should be sortedin such a way that the free information service is selected before a payinformation service.

FIG. 8 also shows information about which mobile carrier the user uses.In this example, both users use mobile carriers, such as a cellularphone carrier. However, the carrier could be network-based, or someother carrier. For example, when a user is traversing a large buildingcomplex, the user could leave the range of an access point and come intorange of another access point. Coverage regions for internal telephonenumbers and building complex information might also change viainformation services. In the example of FIG. 8, USER A uses MOBILECARRIER 1 and USER B uses MOBILE CARRIER 2. This carrier informationallows the location service factory 230 to determine which carrierlocation adapter 225 to use.

FIG. 8 may also be used by the application server 100 owner. Forexample, a cellular phone company may require users to use free serviceswhen there is a choice between the free information service 160 and aninformation service 160 that costs the cellular phone company money forwhich the cellular phone company is not reimbursed by the user.

It is to be understood that the embodiments and variations shown anddescribed herein are merely illustrative of the principles of thisinvention and that various modifications may be implemented by thoseskilled in the art without departing from the scope and spirit of theinvention.

1. A method for switching information services, the method comprisingthe steps of: determining whether a location of a mobile device iswithin a coverage region of a first information service; and redirectingone or more communications for the first information service to a secondinformation service when the location of the mobile device is not withina coverage region of the first information service, wherein the one ormore communications are from an application and wherein the step ofredirecting one or more communications further comprises the step ofredirecting the one or more communications for the first informationservice to a second information service by binding the application to anew information service, and wherein the step of redirecting the one ormore communications for the first information service to a secondinformation service by binding the application to a new informationservice further comprises the step of placing a new reference to a newservice adapter in a service proxy, the new service adapter accessingthe second information service, the new reference replacing an oldreference, the old reference referencing an old service adapteraccessing the first information service.
 2. The method of claim 1,further comprising the step of: selecting the second information serviceby selecting an information service from one or more informationservices having coverage regions encompassing the location of the mobiledevice.
 3. The method of claim 1, further comprising the steps of:determining whether the first information service has failed; andredirecting the one or more communications for the first informationservice to the second information service when the first informationservice has failed.
 4. The method of claim 1, wherein the step ofdetermining whether a location of a mobile device is within a coverageregion of a first information service further comprises the step ofperiodically determining whether a location of a mobile device is withina coverage region of a first information service.
 5. The method of claim4, wherein the step of periodically determining whether a location of amobile device is within a coverage region of a first information servicefurther comprises the step of periodically determining, by usingpredetermined criteria, a candidate list of information services.
 6. Themethod of claim 5, wherein the predetermined criteria comprises one ormore preferences and wherein the candidate list is sorted in order ofthe one or more preferences.
 7. The method of claim 5, wherein the stepof periodically determining, by using predetermined criteria, acandidate list of information services further comprises the step ofselecting an information service having a highest value according to thepredetermined criteria from the candidate list, and wherein the step ofredirecting one or more communications further comprises redirecting theone or more communications for the first information service to theinformation service having the highest value in the candidate list whenthe first information service is not the information service having thehighest value in the candidate list.
 8. The method of claim 5, whereinthe step of periodically determining, by using predetermined criteria, acandidate list of information services further comprises the steps ofdetermining whether the first information service is in the candidatelist, and allowing the one or more communications to the firstinformation service when the first information service is in thecandidate list.
 9. The method of claim 1, wherein the mobile deviceaccesses an application bound to the first information service.
 10. Themethod of claim 1, further comprising the step of creating a candidatelist of information sources by using predetermined criteria.
 11. Themethod of claim 10, wherein the predetermined criteria comprise apreference defined by more than one compatibility sets, eachcompatibility set comprising a name and at least one value.
 12. Themethod of claim 10, wherein the predetermined criteria comprise one ormore of a coverage region, one or more compatibility names, one or moreformats, a cost and one or more specialty preferences.
 13. The method ofclaim 10, wherein the predetermined criteria comprise user preferences.14. The method of claim 13, wherein the user preferences comprise one ormore of a cost preference and a replacement preference, wherein thereplacement preference comprises one of aggressive placement, nopreference, and non-aggressive replacement.
 15. The method of claim 1,further comprising the steps of: comparing one or more compatibilitysets with properties of the first information service in order todetermine whether properties of the first information set meetrequirements of the one or more compatibility sets; redirecting the oneor more communications for the first information service to the secondinformation service when the properties of the first information servicedo not meet the requirements of the one or more compatibility sets; anddetermining that properties of the second information service do meetthe requirements of the one or more compatibility sets.
 16. The methodof claim 1, wherein the step of redirecting the one or morecommunications further comprises the steps of instantiating the newservice adapter and deleting the old service adapter.
 17. An article ofmanufacture for switching information services, comprising: a computerreadable medium containing one or more programs which when executedimplement the steps of: determining whether a location of a mobiledevice is within a coverage region of a first information service; andredirecting one or more communications for the first information serviceto a second information service when the location of the mobile deviceis not within a coverage region of the first information service,wherein the one or more communications are from an application andwherein the step of redirecting one or more communications furthercomprises the step of redirecting the one or more communications for thefirst information service to a second information service by binding theapplication to a new information service, and wherein the step ofredirecting the one or more communications for the first informationservice to a second information service by binding the application to anew information service further comprises the step of placing a newreference to a new service adapter in a service proxy, the new serviceadapter accessing the second information service, the new referencereplacing an old reference, the old reference referencing an old serviceadapter accessing the first information service.
 18. An apparatus forswitching information services, comprising: a memory; and at least oneprocessor, coupled to the memory, operative to: determine whether alocation of a mobile device is within a coverage region of a firstinformation service; and redirect one or more communications for thefirst information service to a second information service when thelocation of the mobile device is not within a coverage region of thefirst information service, wherein the one or more communications arefrom an application and wherein the at least one processor is furtheroperative, when redirecting one or more communications, to redirect theone or more communications for the first information service to a secondinformation service by binding the application to a new informationservice, and to place a new reference to a new service adapter in aservice proxy, the new service adapter accessing the second informationservice, the new reference replacing an old reference, the old referencereferencing an old service adapter accessing the first informationservice.
 19. The apparatus of claim 18, wherein the at least oneprocessor is further operative to: select the second information serviceby selecting an information service from one or more informationservices having coverage regions encompassing the location of the mobiledevice.
 20. The apparatus of claim 18, wherein the at least oneprocessor is further operative to: create a candidate list ofinformation sources by using predetermined criteria.
 21. The apparatusof claim 18, wherein the at least one processor is further operative,when determining whether a location of a mobile device is within acoverage region, to periodically determine, by using predeterminedcriteria, a candidate list of information services.
 22. The apparatus ofclaim 21, wherein the at least one processor is further operative: whenperiodically determining whether a location of a mobile device is withina coverage region, to select an information service having a highestvalue according to the predetermined criteria from the candidate list;and when redirecting, to redirect the one or more communications for thefirst information service to the information service having the highestvalue in the candidate list when the first information service is notthe information service having the highest value in the candidate list.23. The apparatus of claim 21, wherein the at least one processor isfurther operative, when periodically determining whether a location of amobile device is within a coverage region, to determine whether thefirst information service is in the candidate list, and to allow the oneor more communications to the first information service when the firstinformation service is in the candidate list.
 24. A method for switchinginformation services, the method comprising the steps of: determiningwhether a location of a mobile device is within a coverage region of afirst information service; and redirecting one or more communicationsfor the first information service to a second information service whenthe location of the mobile device is not within a coverage region of thefirst information service.
 25. An apparatus for switching informationservices, comprising: a memory; and at least one processor, coupled tothe memory, operative to: determine whether a location of a mobiledevice is within a coverage region of a first information service; andredirect one or more communications for the first information service toa second information service when the location of the mobile device isnot within a coverage region of the first information service.